Nishitetsu Bus Fares

How much are the fares of Nishitetsu Bus in Fukuoka? Do they have flat fares? Could I use Fukuoka Tourist City Pass to pay for the bus fares?

How much are the fares of Nishitetsu Bus in Fukuoka?

Generally 230 yen, except in the center of Fukuoka (between Hakata and Tenjin) where it is just 100 yen and for short rides to/from a subway station in which case it is also 100 yen.

Could I use Fukuoka Tourist City Pass to pay for the bus fares?

Yes. Inside the city borders.

Well actually, the outer parts of the city are not covered by the Fukuoka Tourist City Pass. You can see the coverage area on
http://search.yokanavi.com/touristpass/touristpass_01.pdf

But actually, a lot of the best sights are not far from a subway station, so a subway day pass might be all you need. To look up Nishitetsu bus timetables though, you can use their site:
http://jik.nishitetsu.jp/menu?lang=en

And to see the best of what the city offers, there is:
http://www.thejapanfaq.com/fukpic.html
https://www.youtube.com/playlist?list=PL7LcPcmoSg-j4RLa6iC7ayvBAbOn8-0...